GAIL 
Hydrogen  ion  concentration 


QK 
569 
F95 
G25 


LIBRARY 

THE  UNIVERSITY 
OF  CALIFORNIA 

SANTA  BARBARA 


PRESENTED  BY 
FRED   E.    CLEMENTS 


The  University  of  Washington 
Department  of  Botany 


Hydrogen  Ion  Concentration  and  Other  Factors 
Affecting  the  Distribution  of  Fucus 

by 

FLOYD  WHITNEY  GAIL 


A  Thesis  Submitted  in  Partial  Fulfilment  of  the  Requirements  for 
the  Degree  of  Doctor  of  Philosophy 


Seattle 

Department  of  Printing,  University  of  Washington 
1920 


LIBRARY 

UNIVERSITY  OF  CALIFORNIA 
SANTA  BAUJBARA 


Hydrogen  Ion  Concentration  and  Other  Factors 
Aftecting  the  Distribution  of  Fucus 


FLOYD  W.  GAIL 

University  of   Washington,  Seattle 


INTRODUCTION 

During  the  summer  of  1918  the  writer  worked  on  the  effect  of  light 
and  desiccation  on  the  distribution  of  Fucus  evanescens  Agardh.  In 
places,  however,  little  or  no  Fucus  was  found  where  there  was  sufficient 
light  and  where  desiccation  to  any  considerable  extent  did  not  occur. 
Fucus  frequently  did  not  occur  in  bays  which  had  light  as  well  as  suitable 
places  for  attachment.  The  writer  has  never  found  growing  Fucus  in 
tide-pools,  although  some  were  completely  surrounded  by  it.  Fucus  does 
not  grow  where  Ulva  is  found  in  any  considerable  quantity.  Both  Fucus 
and  Ulva  utilize  the  CO2  in  the  sea-water  during  the  day  in  the  synthe%is 
of  their  carbohydrates,  thus  causing  the  water  to  become  more  alkaline. 
During  the  night  CO2  is  given  off,  thus  causing  the  water  to  become  more 
acid.  Animals  also  add  to  the  acidity  of  the  water.  Tests  showed  the 
hydrogen  ion  concentration  to  be  much  higher  where  Ulva  grew  than 
where  Fucus  grew. 

HISTORICAL 

Little  work  has  been  done  on  the  factors  causing  the  distribution  of 
Fucus.  Davis  (1911)  says  the  depth  to  which  certain  algae  may  descend 
depends  upon  the  penetration  of  light.  The  factor  that  determines  the 
lowest  limits  of  algal  life  is  not  the  depth  of  the  water  but  the  absence  of 
light.  The  green  algae  require  the  most  light,  the  red  the  least  and  the 
browns  are  intermediate.  The  same  writer  also  considers  that  the  influence 
of  temperature  must  be  of  fundamental  importance  in  the  distribution  of 
algae  where  the  seasonal  extremes  are  as  great  as  those  of  the  summer  and 
winter  at  Woods  Hole.  There  Fucus  is  found  in  its  best  vegetative  con- 
dition during  winter  and  spring,  fruiting  most  abundantly  during  the 
latter  season.  It  is  represented  during  the  summer  by  dwarfish  growths, 
frequently  lighter  in  color  than  the  winter  condition  in  which  the  growth 
and  fruiting  is  more  uniform.  Most  of  the  winter  growth  matures  during 
the  spring,  hence  the  display  of  Fucus  during  the  summer  is  comparatively 
poor. 

Gail  (1918)  found  that  light  and  desiccation  are  controlling  factors  in 
the  distribution  of  Fucus. 

(287) 


288  Pub.  Pugei  Sound  Bud.  Sta.  VOL.  2,  No.  51 

Little  work  has  been  done  dealing  with  the  effect  of  hydrogen  ion 
concentration  on  plants,  and  no  literature  was  found  dealing  with  its 
effect  on  Fucus.  Gillespie  (1918)  found  the  growth  of  the  potato  scab 
(Actinomycoses  chromogenus)  in  media  at  the  exponent  5.2  was  slower 
and  generally  less  vigorous  than  at  less  acid  exponents.  Sometimes  the 
strain  succeeded  in  growing  well  in  a  medium  which  had  initially  an  ex- 
ponent of  5.2  or  even  4.8,  but  the  growth  was  accompanied  by  a  marked 
decrease  of  acidity,  and  the  manner  of  the  growth  gave  reason  to  doubt 
whether  even  in  these  cases  more  than  a  poor  growth  can  occur  in  such 
exponents. 

Cohen  and  Clark  (1919)  find  in  several  species  of  Bacillus  that  there 
is  a  broad  zone  of  pH  within  which  the  rates  of  growth  are  quite  uniform 
for  these  short  periods  during  which  the  increase  of  viable  cells  approaches 
the  logarithmic  rate.  On  borders  of  these  zones  of  pH  slight  change  in 
the  pH  produces  marked  effect  upon  reproduction. 

*  Itano  and  Neill  (1919)  report  that  Bacillus  subtilis  germinates  at 
25°  and  37°  C  if  the  hydrogen  ion  concentration  of  the  broth  is  kept  be- 
tween pH  5  and  pH  10  but  not  higher  or  lower  pH  values. 

Shelford  (1918)  found  that  death  among  young  herring  occurred 
after  an  exposure  of  8  hours  when  the  pH  was  brought  down  to  6.825  or 
just  on  the  acid  side  of  true  neutrality.  Lillie,  Loeb,  Medes  and  Moore 
have  gotten  similar  results  on  sperms  and  newly  fertilized  eggs. 

METHODS  AND  MATERIALS 

Experiments  were  started  in  June,  1919,  at  the  Puget  Sound  Biologi- 
cal Station  to  determine  if  the  hydrogen  ion  concentration  had  any  bearing 
on  the  distribution  of  Fucus. 

The  salts  used  were  potassium  acid  phosphate  (KH2PO4),  boric  acid 
(H3BO3),  potassium  chloride  (KC1)  and  sodium  hydroxide  (NaOH). 
The  first  three  salts  were  recrystalized  from  3  to  5  times.  In  all  essentials 
the  methods  used  were  those  of  Clark  and  Lubs  (1917). 

The  sodium  hydroxide  was  prepared  from  metallic  sodium.  A  piece 
larger  than  would  be  required  was  placed  in  a  paraffined  bottle  which  con- 
tained sufficient  conductivity  water  to  cover  the  sodium.  The  mouth  was 
closed  with  a  paraffined  stopper.  The  solution  was  poured  off  and  dis- 
carded when  the  outer  layer  had  dissolved  and  approximately  the  desired 
amount  of  the  unoxidized  sodium  remained.  At  once,  and  as  rapidly  as 
possible,  unused  conductivity  water  was  poured  on  the  sodium  in  the  paraf- 
fined bottle  and  the  mouth  was  closed  with  a  paraffined  stopper.  After 
2-1  hours,  when  the  sodium  had  thoroly  interacted  with  the  water,  the  de- 
sired normality  of  the  solution  was  obtained  by  adding  a  sufficient  amount 


1919  Gail;  on  Fucus  and  Hydrogen  Ion  289 

of  conductivity  water  and  titrating  with  benzoic  acid  99.90%  pure  fused, 
Bureau  of  Standards.  All  other  solutions,  including  the  buffers,  were 
made  according  to  the  methods  of  Clark  and  Lubs  (1917).  These  solu- 
tions were  also  kept  in  paraffined  bottles  or  resistance  glass. 

The  conductivity  water  was  prepared  by  the  distillation  of  barium 
hydroxide  (Ba  (OH)2)  sat.  sol.  lOOcc,  barium  chloride  (BaCl2)  sat.  sol. 
75  cc,  alkaline  potassium  permanganate  sol.*  50  cc,  and  enough  distilled 
water  to  make  2  liters.  The  first  and  last  600  cc  of  distillate  were  dis- 
carded. The  conductivity  water  and  buffers  were  tested  with  the  calomel 
cell. 

The  indicators  used  were  phenolsulphonphthalein  and  o-cresolsulphon- 
phthalein.  A  hydrogen  set  put  up  by  Hynson,  Westcott  and  Dunning  of 
Baltimore  was  also  used,  and  proved  very  helpful  as  a  check. 

pH   DETERMINATIONS 

Tests  were  made  on  alternate  days  for  the  hjrdrogen  ion  concentra- 
tion during  the  last  half  of  June,  thru  the  entire  month  of  July,  and  thru 
the  greater  part  of  August.  They  were  made  in  the  following  locations: 

I.  Places  where  Fucus  was  abundant. 

1.     Sunny  exposure  on  Brown  Island. 

2.  Southeast  half  of  Turn  Rock. 

3.  Southeast   exposure   on   San   Juan   Island   opposite   Madrona 
Point. 

4.  On  beaches  having  good  rock  for  attachment  of  Fucus,  much 
light  and  little  or  no  Ulva. 

II.  Places  where  little  or  no  Fucus  grew. 

5.  On  beaches  having  good  attachment,  good  light  and  an  abun- 
dant growth  of  Ulva. 

6.  In  tide-pools  containing  no  Fucus  but  with  an  abundant  growth 
of  it  about  them. 

7.  Out  in  the  Sound  away  from  visible  vegetation. 

8.  On   beaches   having  poor   attachment   for  Fucus,   much   light 
and  little  or  no  Ulva. 

9.     Locations  having  little  or  no  direct  sun  light. 


KaOH  200g.,   KMnO,   SR.,   distilled  in  H^O  made  up  to  1000  cc. 


290 


Pub.  Puget  Sound  Biol.  Sta. 


VOL.  2,  No.  51 


TABLE  1.     Average  monthly  pH  values  of  sea-water 
June  15  to  August  15,  1919. 


June                 July                August 

Av.  for  Per. 

Time  of  Testing 

Location 
1  Southeast  exposure 
2            "               " 
3 
4  Beach,  good  attachment 

a.m. 
5-6 

7.8 

7.81 
7.8 
7.6 

p.m. 
1:4 

8.37 
8.3 
8.175 
8.0 

a.m. 
_5-6 

7.65 
7.8 
7.77 
7.72 

p.m. 
1-4 
Much 
8.15 
8.26 
8.23 
8.27 

a.m. 
5-6 
Fucus 
7.73 
7.8 
7.75 
7.53 

p.m. 
1-4 

8.35 
8.15 
8.25 
8.2 

1  a.m. 
1    5-6 

7.72 
7.80 
7.77 
7.62 

p.m. 
1-4 

8.31 

8.23 
8.21 
8.16 

Little  or  no  Fucus 

S  Beach,  Ulva  present 
6  Tide  pools 
7  Out  in  Sound 
8  Gravel  beach;  no  Ulva 
9  Little  direct  sunlight 

7.71 
7.41 
7.90 
7.90 
7.91 

8.60 
8.45 
8.00 
8.00 
8.13 

7.56 
7.23 
8.00 
8.10 
7.84 

8.73 
8.62 
8.16 
8.20 
8.15 

7.80 
7.66 
8.14 
8.00 
8.03 

8.80 
8.70 
8.25 
8.15 
7.97 

7.69 
7.43 
8.01 
8.00 
7.92 

8.71 
8.59 
8.15 
8.12 
8.07 

Table  1  shows  the  different  pH.  values  of  the  seawater  and  the  loca- 
tions are  referred  to  by  numbers  which  correspond  to  those  above.  The 
pH  value  of  the  locations  having  much  Fucus  does  not  vary  much  either 
side  of  8.0  in  the  afternoons.  The  average  difference  between  the  forenoon 
and  the  afternoon  is  0.50.  In  case  of  tidepools  and  of  beaches  having 
much  Ulva,  but  neither  having  Fucus,  the  pH  values  of  the  water  in  the 
afternoons  is  considerably  above  that  of  8.00.  The  average  difference 
between  the  forenoon  and  afternoon  is  1.09,  which  is  much  greater  than 
the  average  difference  where  much  Fucus  is  found.  This  would  seem  to 
indicate  that  the  pH  values  of  the  water  were  not  favorable  since  all  other 
conditions  were  good. 

The  last  three  locations,  namely  (7)  out  iri  the  Sound  away  from 
visible  vegetation,  (8)  on  beaches  having  no  Ulva  and  (9)  on  exposures 
receiving  little  or  no  direct  sunlight,  have  pH  values  well  within  the 
limits  for  a  good  growth  of  Fucus.  They  have  an  average  difference 
between  the  morning  and  afternoon  of  only  0.035.  There  must  be  other 
factors  which  prohibit  the  growth  of  Fucus  in  these  locations,  and  these 
factors  will  be  considered  in  a  later  part  of  this  paper. 

EFFECTS  OF  ULVA  ON  Fucus 

To  study  the  effect  that  Ulva  might  produce  on  Fucus,  2-4-lobed 
plants,  and  more  mature  ones  but  not  fruiting,  with  their  natural  attach- 
ments, were  selected.  These  were  placed  in  the  Sound,  where  much  Ulva 
tvas  growing,  others  in  Fucus  beds.  All  plants  were  apparently  of  equal 
vigor.  A  stout  cord  was  tied  to  each  rock  containing  the  Fucus  plants 
which  were  placed  among  the  Ulva.  To  the  other  end  of  each  cord  a 
piece  of  wood  was  tiedv  The  cord  was  of  sufficient  length  to  permit  the 
wood  to  float  at  high  tide.  Thus  the  Fucus  could  readily  be  found.  The 
i-ocks  containing  the  Fucus  which  was  placed  in  the  Fucus  beds  were  suffi- 


1919  Gail;  on  Fucus  and  Hydrogen  Ion  291 

ciently  heavy  to  hold  them  in  place,  and  they  were  less  difficult  to  find 
than  among  the  Ulva.  There  were  six  rocks  bearing  the  2-4-lobed  Fucus 
plants  and  the  same  number  bearing  the  more  mature  plants  among 
the  Ulva.  The  same  number  of  each  kind  were  placed  in  the  Fucus  beds. 
All  were  placed  about  1.5  meters  vertically  above  the  — 1  tide  line. 

After  three  weeks  both  the  young  and  mature  Fucus  plants  placed 
among  the  Ulva  had  become  much  darker  in  color,  and  by  the  end  of  4.5 
weeks  they  had  a  decidedly  reddish  tinge.  This  is  an  abnormal  color. 
At  the  end  of  11  weeks  the  reddish  tinge  was  still  present  except  for  a 
space  of  3.5  mm  around  the  tip  ends  and  margin  of  the  thallus  where  they 
were  very  dark  thruout.  A  microscopic  examination  of  sections  thru  the 
thallus  showed  a  very  evident  gradient  of  susceptibility.  The  cells  at  the 
margin  were  dark  brown  in  color  and  the  walls  were  in  a  state  of  collapse. 
A  little  farther  in  they  were  still  intact  but  the  protoplasm  was  very  dark. 
In  cells  still  farther  in,  the  protoplasm  was  more  normal  in  color  and 
normal  chloroplasts  could  be  detected.  The  plants  had  the  same  number 
of  lobes  that  they  had  in  the  beginning  of  the  experiment.  Measurements 
showed  that  on  the  average  they  had  not  increased  in  size. 

Both  the  young  and  the  mature  plants  placed  in  the  Fucus  beds  had 
normal  color  at  the  end  of  1 1  weeks.  The  young  plants  placed  in  the 
Fucus  bed  had  grown  to  twice  the  size  of  the  young  plants  placed  among 
the  Ulva.  A  microscopic  examination  showed  the  cells  to  be  normal. 

The  average  pH  value  of  the  water  about  the  Ulva  at  about  6:00  A. 
M.  was  7.85.  and  at  about  2:00  P.  M.  was  8.72.  The  average  pH  value 
of  the  water  about  Fucus  at  about  6:00  A.  M.  was  7.88,  and  at  about 
2:00  P.  M.  was  8.21.  The  average  temperature  of  the  water  among 
the  Ulva  was  18°  C  at  about  2:00  P.  M.  The  average  lower  extreme  was 
11°  C.  The  light  was  of  the  same  intensity  since  they  were  the  same 
distance  above  a  — 1  tide  and  were  on  the  same  exposure.  All  conditions 
seemed  to  be  the  same  except  that  of  the  pH  value  of  the  water.  The  dif- 
ference in  growth  and  color  in  this  experiment  points  toward  the  difference 
in  the  pH  values  of  the  water  in  the  two  locations,  as  a  means  by  which 
the  presence  of  Ulva  may  limit  the  distribution  of  Fucus. 

EFFECT  OF  pH  AND  TEMPERATURE  ON  YOUNG  PLANTS 

Experiments  were  started  to  study  the  effect  on  Fucus  plants  of  pH 
values  on  the  acid  side  of  true  neutrality  and  on  up  thru  the  higher  alka- 
line values. 

Open  4-liter  glass  jars  were  used,  and  three  liters  of  water  were 
used  in  each  jar.  The  water  was  taken  from  the  Sound,  away  from  visible 
vegetation.  It  had  an  average  pH  value  of  8.05.  Commencing  with  pH 
value  of  6.6  each  jar  was  labeled  respectively  6.8,  7.0,  7.2,  etc.,  thru  8.8. 


292  Pub.  Puget  Sound  Biol.  Sta.  VOL.  2,  No.  51 

The  correct  pH  value  from  6.6  to  8.0  was  secured  by  the  addition  of  HC1. 
From  8.2  thru  8.8  the  correct  pH  value  was  secured  by  the  addition  of 
sufficient  amounts  of  \vater  from  about  Ulva.  When  the  tide  was  high  it' 
was  necessary  to  add  NaOH  in  place  of  water  taken  from  about  Ulva. 
In  the  addition  of  both  the  HC1  and  NaOH  a  medicine  dropper  was  used. 
The  indicator  used  for  testing  the  pH  values  was  phenolsulphonphthalein. 
The  hydrogen  ion  set  was  used  wholly  for  the  comparison  of  colors.  In  those 
cases  in  which  the  pH  values  ranged  from  6.6  to  8.0  it  was  necessary  to  make 
the  pH  corrections  of  the  water  nearly  every  hour  of  the  day.  The  number  of 
changes  necessary  depended  largely  upon  the  intensity  of  the  sunlight. 
The  correction  of  the  pH  values  above  8.0  was  necessary  two  or  three 
times  per  day  depending  also  upon  the  intensity  of  the  sunlight.  These 
changes  kept  the  pH  values  of  the  water  reasonably  accurate.  The  sea- 
water  was  changed  completely  in  each  jar  once  each  day. 

The  temperature  of  the  water  in  two  of  the  sets  of  the  experiment 
varied  from  11°  C  to  24°  C.  These  were  the  temperatures  secured  on  the 
float  where  the  jars  remained  during  the  time  of  the  experiment.  The 
temperature  of  the  water  in  the  third  set  varied  from  10.5°  to  13°  C. 
This  temperature  was  obtained  by  suspending  in  the  Sound  trays  with 
bottoms  of  wire  netting.  The  trays  were  fastened  by  cords  between  two 
logs  on  a  float.  The  jars  were  placed  in  the  trays.  The  trays  were  regu- 
lated in  such  a  manner  that  the  surface  of  the  water  in  the  jars  had  the 
same  level  as  the  surface  of  the  water  of  the  Sound.  The  lower  tempera- 
ture, 10.5°  C,  was  the  average  temperature  of  the  water  in  the  jars  at 
night.  The  higher  temperature,  13°  C,  was  the  usual  temperature  at  about 
1:00  P.  M.,  which  was  about  1°  C  higher  than  the  temperature  of  the 
Sound  at  that  time.  Two-lobed  young  Fucus  plants  with  natural  attach- 
ments were  used.  Three  such  sets  were  continued  over  a  period  of  nearly 
11  weeks.  All  conditions  were  the  same  except  that  of  temperature. 

The  results  of  the  two  sets  having  the  temperatures  range  from  11°  C 
to  24°  C  will  be  considered  first.  The  Fucus  plants  in  the  seawater  having 
a  pH  value  of  6.6  and  6.8  lived  about  9  days.  The  thalli  of  the  plants 
commenced  to  curl  on  the  second  day.  They  showed  signs  of  whiteness 
about  the  margins  on  the  third  day.  On  the  fifth  day  the  larger  portion  of 
the  entire  thallus  looked  whitish  and  soft.  A  microscopic  examination  of 
the  cells  on  the  seventh  day  showed  those  near  the  tips  and  margins  to  be 
completely  broken  down.  The  cells  a  little  farther  in  were  very  much 
plasmolyzed.  Still  farther  in,  a  few  of  the  cells  were  apparently  normal. 
No  cells  were  normal  on  the  ninth  day.  Here  also  the  gradient  of  suscep- 
tibility is  well  shown.  These  plants  were  kept  two  weeks  longer  in  the 
seawater  having  their  respective  pH  values.  At  the  end  of  this  time 


1919  Gail;  on  Fucus  and  Hydrogen  Ion  293 

practically  all  of  the  cells  were  broken  down  and  the  plants  were  becom- 
ing frayed.  The  effect  on  the  Fucus  plants  in  seawater  having  pH  values 
of  7.0  and  7.2  was  similar,  but  three  or  four  weeks  were  required  to  bring 
about  the  same  results. 

Those  plants  in  seawater  having  pH  values  of  7.4,  7.6  and  7.8  showed 
little  or  no  effect  except  that  the  growth  was  somewhat  inhibited.  There 
appeared  to  be  a  physiological  adjustment  to  some  extent,  at  least  tempo- 
rarily. Since  Fucus  is  rarely  found  in  seawater  having  a  pH  value  as 
low  as  7.4,  and  this  for  only  a  short  period  in  the  early  morning,  it  would 
seem  that  it  might  be  a  matter  only  of  time  until  the  plants  in  seawater 
having  this  pH  value  and  possibly  the  plants  in  seawater  having  a  pH 
value  of  7.6,  would  show  results  similar  to  those  in  the  lower  pH  values. 

The  plants  in  seawater  having  a  pH  value  of  8.0  to  8.2  had  increased 
on  the  average  1  cm  in  length,  and  about  80  per  cent  of  them  were  4-lobed. 
In  one  jar  containing  seawater  having  the  same  pH  value,  the  Fucus  plants 
had  not  grown  as  much.  These  had  increased  in  length  only  about  7  mm 
but  the  same  percent  of  them  were  4-lobed.  There  was  no  cause  apparent 
for  this  difference  since  the  conditions  were  the  same  and  they  had  received 
the  same  treatment.  There  may  have  been  some  difference  in  the  vigor  of 

I  he  plants  but  they  appeared  the  same  at  the  beginning  of  the  experiment. 
At  the  end  of  1 1  weeks  the  experimental  plants  were  compared  with  those 
on  the  shore  from  which  they  were  taken.     The  growth  was  practically 
the  same.     Those  in  the  jars  having  seawater  with  a  pH  value  of  8.0  to 
8.2  were  slightly  lighter  in  color.     The  cause  was  undoubtedly  due-  in  a 
large  degree  to  the  difference  in  temperature,  as  will  be  explained  later. 

The  Fucus  plants  in  seawater  having  a  pH  value  of  8.4  became  abnor- 
mally darker  after  about  4.5  weeks  and  remained  darker  thruout  the  entire 
time.  They  showed  an  average  increase  in  length  of  3  mm  at  the  end  of 

II  weeks.     Two  of  the  30  plants  in  the  jars  containing  seawater  having  a 
pH  value  of  8.4  had  become  4-lobed. 

The  Fucus  plants  in  seawater  having  pH  values  of  8.6  and  8.8  became 
very  dark  at  the  end  of  the  first  week.  They  also  appeared  more  leathery 
and  soon  took  on  a  reddish  tinge.  A  microscopic  examination  after  8  weeks 
showed  all  the  cells  to  be  dead,  except  those  in  the  interior  part  of  the 
thallus.  The  protoplasm  was  brownish  in  color  and  many  of  the  cell  walls 
near  the  outer  margin  were  collapsing.  Xo  growth  had  taken  place  at  the 
end  of  11  weeks  and  very  few  cells  appeared  normal. 

The  results  from  the  set  having  the  temperature  range  from  10.5°  to 
13°C  will  now  be  considered.  In  jars  containing  seawater  with  pH 
values  of  6.6,  6.8  and  7.0  the  results  were  practically  the  same  as  in  the 
two  previous  sets  except  in  degree  and  in  that  a  longer  period  of  time  was 
required.  No  effects  were  noticeable  until  on  the  8th  day  on  the  Fucus 


294  Pub.  Pu(jet  Sound  Biol.  Sta.  VOL.  2,  No.  51 

in  seawater  having  a  pH  value  of  6.6,  and  none  until  at  the  end  of  three 
weeks  on  those  in  6.8  and  7.0. 

No  effects  could  be  seen  in  7.2,  7.4  and  7.6  except  that  growth  ap- 
peared somewhat  inhibited.  In  7.8  there  was  an  average  increase  in  length 
of  5.5  mm,  and  some  showed  the  beginning  of  four  lobes. 

The  plants  in  seawater  having  pH  values  of  8.0  to  8.2  had  on  the 
average  the  same  growth  as  the  plants  in  the  same  pH  values  but  with  the 
temperatures  ranging  from  11°  to  24°C.  The  color,  however,  was  more 
nearly  the  same  as  the  color  of  the  Fucus  plants  of  the  same  age  growing 
on  the  shore.  This  wide  range  of  pH  values  and  higher  temperature 
must  account  to  considerable  extent  for  the  lighter  color  of  the  Fucus 
plants  in  the  previous  set  having  the  same  pH  values. 

The  Fucus  plants  in  the  seawater  having  pH  values  of  8.4,  8.6  and 
8.8  were  affected  in  practically  the  same  manner  as  in  the  previous  set 
with  the  higher  and  wider  range  of  temperature.  The  period  of  time 
necessary  to  show  the  same  results  was  from  4  to  6  days  longer  in  this 
narrow  range  and  lower  temperature. 

PERCENT  OF  GERMINATION  OF  OOSPORES 

Experiments  were  also  undertaken  with  a  view  to  determining  effects 
both  of  temperature  and  of  pH  values  of  the  seawater  on  the  acid  side  of 
true  neutrality  and  on  up  through  the  higher  alkaline  values,  upon  the 
germination  of  oospores  and  upon  the  subsequent  growth  of  the  sporelings 
produced.  The  oospores  were  obtained  in  the  manner  previously  described 
(Gail,  1918).  They  were  germinated  on  microscopic  slides  placed  in 
glass  jars  containing  seawater  having  the  different  pH  values.  Four  dif- 
ferent ranges  of  temperature,  10.5°-13°C,  11°-17°C,  11°-24°C  and  11°- 
30°  were  used.  The  temperature  of  10.5°-13°C  was  secured  by  suspend- 
ing trays  with  bottoms  of  wire  netting  in  the  Sound  as  was  previously 
described.  The  temperature  of  11°-17°C  was  secured  by  placing  the 
jars  containing  the  different  pH  values  of  seawater  in  porcelain  pans 
containing  seawater,  and  setting  these  on  a  float  on  the  Sound.  The 
pans  were  about  60  cm  high.  The  water  in  the  pans  was  changed  as 
often  as  was  necessary  to  keep  the  temperature  at  17°C  or  below.  The 
temperature  of  the  seawater  having  the  different  pH  values  usually 
went  down  to  11°C  at  night  on  the  float.  The  temperature  of  11°-24°C 
was  the  temperature  produced  by  the  atmosphere  on  the  float  some  dis- 
tance from  the  bank.  The  last  temperature,  11°-30°C,  was  that  pro- 
duced by  the  atmosphere  on  the  float  but  near  the  shore  where  it  was 
protected  from  the  wind.  Each  set  was  run  in  duplicate. 

The  per  cent  of  germination  will  be  considered  first.  An  examina- 
tion of  table  2  will  show  the  following: 


1919 


Gailj  on  Fncus  and  Hydrogen  Ion 


295 


TABLE  2.     Percentage  of  germination  in  different  pH  values  and  temper- 
atures of  water. 


pH 

10.5°-1S°C 

11°-17°C  |   11°-24°C   |  11°-30°C 

8.8 

30 

12 

13 

0 

8.6 

75 

60 

40 

15 

8.4 

90 

90 

67 

20 

8.0-8.2 

95 

92 

85 

20 

7.8 

80 

71 

75 

13 

7.6 

75 

82 

49 

10 

7.4 

60 

60 

41 

3 

7.2 

40 

28 

15 

0 

7.0 

40 

31 

3 

0 

6.8 

36 

10 

5 

0 

6.6 

32 

5 

0 

0 

1.  The    higher   percent   of   germination   occurs   in    seawater   having 
pH  values  above  7.4  and  below  8.6  in  all  temperatures  considered.     The 
maximum  germination  occurs  in  seawater  having  pH  values  between   8.0 
and  8.2. 

2.  The   per  cent   of  germination   usually  diminishes   above   a  tem- 
perature of  17°C. 

3.  A  microscopic  examination  of  the  oospores  in  seawater  having  pH 
values  above   8.2   with  a  temperature  above  24 °C  showed  that  the  cell 
wall  and  plasma  membrane  were  ruptured  and  that  the  protoplasm  was 
exuding. 

PERMEABILITY  OF  OOSPORES 

Experiments  were  now  -made  to  determine  whether  permeability  is 
related  to  inhibition  of  germination  of  oospores  and  to  the  death  of 
oospores  in  different  pH  values  of  seawater.  Oospores  were  secured  in 
the  usual  manner.  These  were  stained  one  to  three  hours  in  a  weak 
neutral  red  solution.  Watch  glasses  were  washed  in  seawater  and  rinsed 
thoroly  with  seawater  having  the  pH  value  that  was  to  be  used  in  that 
particular  watch  glass.  The  watch  glass  was  then  labeled  with  the 
correct  pH  value.  Watch  glasses  for  each  pH  value  used  were  treated 
in  the  same  manner.  A  large  number  of  stained  oospores  "were  now 
placed  in  each  watch  glass  by  means  of  a  medicine  dropper.  The  medi- 
cine dropper  was  also  used  to  place  seawater  having  correct  pH  values 
on  the  stained  oospores.  The  water  on  the  oospores  was  changed  four 
times.  This  was  done  to  make  certain  that  the  correct  pH  value  was  in 
each  glass.,  as  the  oospores  were  stained  in  seawater  having  a  pH  value 
of  8.2. 

During  the  first  attempts  the  oospores  were  examined  every  15 
minutes  under  a  compound  «ii^o*onnc  t/>  nhsrrve  any  change.  As  no 


296  Pub.  Puget  Sound  Biol.  Sta.  Voi^  2,  No.  51 

changes  could  be  detected,  the  time  for  the  examination  was  extended 
to  about  one  hour.  Decided  changes  in  color  usually  occurred  after 
about  12  hours.  Each  oospore  is  covered  with  a  gelatinous  substance 
which  probably  accounts  for  the  long  period  of  time  required  before  any 
definite  changes  resulted.  In  no  case  did  a  change  in  color  take  place  in 
all  oospores. 

Eighty  per  cent  of  the  oospores  in  seawater  having  pH  values  of  6.6 
and  6.8  changed  from  red  to  darker  red  or  purple.  No  change  of  color 
occurred  in  oospores  which  were  in  seawater  having  pH  values  between 
6.8  and  8.2.  This  indicates  that  substances  potentially  acid  or  alkaline 
do  not  permeate  the  plasma  membrane  in  sufficient  quantities  to  change 
the  color  produced  by  staining  the  oospores  with  neutral  red.  Oospores 
in  seawater  having  pH  values  below  7.6  were  not  killed  but  were  in- 
hibited when  the  temperature  was  below  24 °C.  This  was  shown  by  the 
fact  that  when  the  pH  values  were  allowed  to  rise,  germination  and  some 
growth  took  place.  When  the  temperature  of  the  water  was  above 
24 °C  the  oospores  were  killed  in  3  to  24  hours,  depending  upon  the 
height  of  the  temperature.  Better  germination  occurs  in  seawater  hav- 
ing pH  values  between  7.4  and  8.4.  The  maximum  germination  is  at 
about  8.0  or  8.2  and  gradually  decreases  on  either  side.  This  is  in 
accord  with  the  observations  that  the  plasma  membrane  was  not  per- 
meated by  OH  or  H  ions  in  any  considerable  quantity  in  these  pH 
values  as  is  manifest  by  no  change  in  color.  In  seawater  having  pH 
values  of  8.4,  8.6  and  8.8  about  70  per  cent  of  the  oospores  changed 
from  red  to  yellow.  Usually  there  was  a  considerable  space  between 
the  cell  wall  and  the  protoplast.  The  OH  ion  had  probably  produced  a 
sufficient  disturbance  of  the  colloidal  equilibrium  of  the  plasma  mem- 
brane to  bring  about  plasmolysis.  Harvey  (1911)  reports  injury  to  be 
possible  when  the  concentration  of  the  base  was  0.025N. 

Plate  51  shows  a  graphic  representation  of  the  germination  during 
the  first  7  days  at  different  temperatures  and  the  various  pH  values 
of  the  seawater. 

GROWTH  OF  SPORELINGS 

Oospores  were  germinated  in  the  usual  manner  and  the  sporelings 
were  grown  for  four  weeks.  The  same  conditions  and  manner  of  treat- 
ment were  continued  that  were  used  in  the  study  of  the  per  cent  of 
germination  of  oospores.  The  percentage  of  living  sporelings  is  based 
on  the  number  of  oospores  that  had  germinated  by  the  seventh  day. 
Table  3  shows  the  percentage  of  living  sporelings  at  the  end  of  four 
weeks  together  with  the  pH  values  of  the  water  and  the  variations  in  the 


1919 


Gail;  on  Fucus  and  Hydrogen  Ion 


297 


temperature.  With  a  few  exceptions  there  is  a  gradual  decrease  in  the 
number  of  living  sporelings  as  the  temperature  becomes  higher  than 
17°C.  The  percentage  of  living  sporelings  is  very  small  when  the  tem- 
perature reaches  30°C.  The  maximum  number  is  nearly  always  found 
in  water  having  pH  values  of  8.0  to  8.2.  For  a  graphic  representation 
see  plate  51. 

TABLE  3.     Percent  of  living  sporelings  at  the  end  of  4  weeks,  in  different 
temperatures  and  pH  values 


10.5°C-13°C 


|    11°C-24°C     |     11°C-30°C 


8.8 

0 

0 

0 

0 

8.6 

29 

30 

22 

0 

8.4 

56 

83 

70 

45 

8.0-8.2 

96 

98 

81 

5 

7.8 

86 

90 

82 

3 

7.6 

85 

91 

81 

4 

7.4 

52 

40 

26 

0 

7.2 

45 

28 

7 

0 

7.0 

45 

29 

0 

0 

6.8 

20 

8 

2 

0 

6.6 

19 

3 

0 

0 

The  size  of  the  sporelings  growing  in  seawater  having  the  various 
pH  values  and  a  temperature  ranging  from  11°-17°C  were  recorded 
at  frequent  intervals.  Both  the  length  and  the  width  of  the  sporelings 
were  measured.  The  increase  in  width  is  very  small  during  this  period 
of  growth  and  will  be  considered  later  in  this  article.  Each  measure- 
ment recorded  represents  the  average  length  and  width  of  12  typical 
sporelings.  Very  little  growth  occurred  in  seawater  having  a  pH  value 
of  6.6.  The  sporelings  were  still  alive  at  the  end  of  four  weeks,  as  they 
increased  in  length  from  0.104  mm  to  0.16  mm  when  the  pH  value  of  the 
sea  water  was  raised  from  6.6  to  7.4. 

The  growth  of  sporelings  in  seawater  having  pH  values  of  7.0  and 
7.2  was  almost  completely  inhibited  after  the  eighth  day. 

The  growth  in  seawater  having  pH  values  of  7.4,  7.6  and  7.8  was 
very  much  the  same.  Growth  was  inhibited  to  some  extent  after  about 
two  weeks. 

No  inhibition  of  growth  is  apparent  in  seawater  having  pH  values 
of  8.0-8.2.  Numerous  sets  of  experiments  showed  the  same  results 
in  all  temperatures  tried  below  24 °C.  The  sporelings  increased  in  length 
from  0.072  mm  to  0.192  mm  in  72  hours.  This  was  an  increase  of  .12 
mm.  By  the  eighth  day  the  length  was  0.404  mm.  Growth  continued 
thruout  the  period. 


298 


Pub.  Puget  Sound  BioL   Sta. 


VOL.  2,  No.  51 


The  sporelings  in  seawater  having  a  pH  value  of  8.4  increased 
from  0.072  mm  to  0.224  mm  in  the  first  72  hours.  This  was  an  increase 
of  0.152  mm,  which  was  a  greater  increase  than  occurred  in  seawater 
having  a  pH  value  of  8.0-8.2.  By  the  eighth  day  the  length  was  0.30 
mm,  and  by  the  thirteenth  day  it  was  0.332  mm,  an  increase  of  only 
0.032  mm  in  five  days,  while  the  sporelings  in  the  seawater  having  pH 
values  of  8.0-8.2  were  0.40  mm  long  in  the  same  time.  Growth  seems 
to  be  inhibited  after  about  72  hours  in  seawater  having  a  higher  pH 
value  than  8.2. 

The  sporelings  growing  in  seawater  having  a  pH  value  of  8.6  were 
living  at  the  end  of  four  weeks.  At  this  time  they  were  0.24  mm  in 
length,  an  increase  of  0.178.  The  growth  was  quite  rapid  for  the  first 
eight  days,  when  it  was  practically  inhibited,  and  many  appeared  dead 
by  the  eighteenth  day.  A  considerable  number  of  the  sporelings  became 
loosened  from  the  slide  during  the  remainder  of  the  four  weeks. 

The  sporelings  growing  in  seawater  having  a  pH  value  of  8.8  grew 
very  slowly  and  life  was  considered  extinct  after  the  seventh  day.  No 
growth  took  place  after  this  time  and  the  sporelings  were  dark  gray 
instead  of  brown  in  color.  Many  of  the  sporelings  soon  became  loosened 
from  the  slide.  The  length  of  the  sporeling  on  the  seventh  day  was  0.08 
mm.  As  the  oospore  is  about  0.072  mm  in  diameter,  the  sporeling  had 
increased  0.008  mm  in  length  in  seven  days.  For  a  graphic  representa- 
tion of  this  increase  in  length  see  plate  52. 

The  effect  of  different  pH  values  and  temperatures  on  the  size  of 
sporelings  as  measured  by  width  and  length  at  the  end  of  four  weeks 
is  summarized  in  table  4,  from  which  the  following  is  evident: 

TABLE  4.     Size  of  sporelings  in  different  p  H  values  and  different  tem- 
peratures of  water  at  the  end  of  4 


pH 

10.5°C-13°C 

11°( 

M7°C 

11° 

C-24°C     | 

11°C-30°C 

width 

length 

width 

length 

1    width 

length 

width 

length 

8.8 

•>.. 

0-t 

0.. 

0- 

n      ! 

o., 

0 

8.6 

90 

320 

90 

214 

69 

123.5 

0 

0 

8.4 

90 

384 

90 

396 

78 

217.5 

78 

116 

R.0-8.2 

96 

640 

112 

680 

89 

288 

80 

168 

7.8 

88 

496 

92 

336 

84 

288 

76 

128 

76 

90 

502             90 

256 

69 

208 

76 

96 

7.4 

72 

388             90 

272 

75 

276 

0 

0 

7.2 

76.8 

416             90 

208 

72 

144 

76 

102 

70 

76 

320             78 

176 

78 

88 

0 

0 

6.8 

76 

240            76 

128* 

78 

81 

0 

0 

6.6 

76 

208            76 

160 

0 

0    ! 

*  Dead  on  24th  dav. 


1919  Gail;  on  Fucns  and  Hydrogen  Ion  299 

1.  The  maximum  growth  is  found  in  seawater  having  a  temperature 
not  higher  than  17°C. 

2.  The  largest  plants  as  a  rule  are  found  in  seawater  having  a  pH 
value  of  8.0-8.2,  in  any  of  the  temperatures  considered. 

3.  The   growth   in   width  of  the   sporeling   is   small   in   comparison 
with   the    growth    in    length.      The    greatest   growth    in    width   is    found 
where  the  temperature  of  the  water  is  not  higher  than  17°C,  and  where 
the  pH  value  of  the  water  is  8.0-8.2.     Plate  51  shows  a  graphic  repre- 
sentation of  the  size  of  the  sporelings  as  affected  by  the  different  tem- 
peratures and  the  various  pH  values.     It  will  be  observed  that  in  this 
particular  set  the   sporelings  made  little   or  no  growth  where  the  tem- 
perature  ranged  from   11°-17CC  and  the  water  had  a  pH  value  of  6.8. 
The  sets  were  all  run  in  duplicate  and  there  was  a  more  normal  growth 
in  the  corresponding  set  of  the  same  pH. 

STUDY  OF  BEACHES 

In  the  case  of  beaches  having  neither  Ulva  nor  Fucus  and  only 
smooth  rolling  stones  for  attachment,  some  other  factor  or  factors  than 
that  of  the  pH  value  of  the  water  must  be  responsible  since  the  average 
pH  value  of  the  water  at  such  places  was  8.07,  which  is  well  within  the 
limits  for  an  abundant  growth  of  Fucus.  Experiments  previously  con- 
ducted by  the  writer  (Gail,  1918)  threw  some  light  on  the  situation. 
It  was  then  believed  that  desiccation  was  the  limiting  factor.  Consider- 
ing the  evidence  presented  in  this  paper,  it  is  now  considered  ,tha*.  tem- 
perature is  also  an  important  factor. 

As  during  the  previous  summer,  oospores  were  planted  on  smooth 
flat  stones  which  were  firmly  attached  to  the  beach,  a  10  per  cent  ger- 
mination resulted  on  two  different  occasions  when  the  temperatures  did 
not  go  above  19°  or  20° C.  At  another  time  scarcely  a  1  per  cent  ger- 
mination resulted,  when  the  temperature  remained  at  26 °C  for  nearly  4 
hours.  In  one  case  all  of  the  sporelings  disappeared  in  five  days.  In 
another  trial  they  disappeared  in  eight  days.  In  the  last  trial,  during 
which  it  was  more  cloudy  than  usual,  most  of  the  sporelings  remained 
on  the  stones  until  the  thirteenth  day.  The  temperature  in  the  first  case 
went  up  to  24°,  24.5°  and  26°C,  during  the  first  three  days.  When  the 
sporelings  remained  on  the  stones  eight  days  the  temperature  rose  to 
26 °C  on  two  different  days,  but  only  for  about  an  hour  on  each  occasion. 
In  the  last  case  the  temperature  did  not  go  higher  than  20 °C  until  the 
last  two  days,  when  it  rose  to  25°C  and  28°C,  respectively.  The  tem- 
perature of  28°C  was  maintained  for  over  two  hours. 

In  order  to  determine  whether  desiccation  or  temperature  was  the 
limiting  factor  experiments  were  started  as  follows.  Oospores  were 


300  Pub.  Puget  Sound  BioL  Sta.  VOL.  2,  No.  51 

planted  on  glass  slides  and  placed  in  three  different  glass  jars  each  con- 
taining two  liters  of  sea  water  having  a  pH  value  of  8.2.  The  tempera- 
ture of  one  jar  did  not  go  higher  than  13°C.  In  a  second  jar  it  did  not 
go  higher  than  17°C.  In  a  third  jar  it  did  not  go  above  27 °C.  Each 
jar  contained  two  slides  and  each  slide  contained  over  75  oospores.  A 
95  per  cent  germination  took  place  in  those  jars  in  which  the  tempera- 
ture varied  from  11°  to  17°C.  About  a  3  per  cent  germination  resulted 
in  those  jars  in  which  the  temperature  went  as  high  as  27  °C,  when  this 
high  temperature  was  maintained  2  hours  or  more.  In  these  experi- 
ments the  desiccation  factor  was  eliminated  and  the  effect  of  tempera- 
ture was  clearly  demonstrated.  Undoubtedly  desiccation  on  the  beach 
is  harmful  to  the  germination  of  oospores  and  the  growth  of  sporelings 
but  the  high  temperatures  often  reached  may  be  the  determining  factor 
if  they  continue  any  considerable  length  of  time. 

STUDY  OF  TIDEPOOLS 

A  study  of  tidepools  was  also  made  in  order  to  find  why  Fucus  does 
not  grow  in  them.  Chambers  (1912)  claims  that  young  plants  of  Prionitis 
lyallii  are  always  found  starting  around  the  rim  of  tidepools  where  the 
CO2  would  supposedly  be  abundant,  but  never  on  the  bottom,  where  both 
CO2  and  oxygen  would  in  all  probability  be  absent  or  much  diminished. 
He  believes  the  whole  problem  would  resolve  itself  into  a  question  of 
aeration.  The  writer  has  made  numerous  tests  in  tidepools  and  found 
that  the  average  pH  value  of  the  seawater  in  them  between  1 :00  P.  M. 
and  4:00  P.  M.  was  8.59,  and  that  it  was  often  8.8.  This  is  partly 
brought  about  by  the  seawater  draining  from  the  surrounding  Fucus 
beds  into  the  tidepools  when  the  tide  is  going  out.  As  the  seawater 
makes  its  way  down  into  the  tidepools,  it  is  continually  taking  up  oxygen 
and  is  well  aerated.  The  microscopic  algae  and  Prionitis  lyallii  also 
make  the  water  more  alkaline  in  the  manufacture  of  their  carbohydrates. 
During  the  night  CO2  is  liberated  largely  and  oxygen  is  used  in  respira- 
tion. This  CO2  unites  with  H2O,  forming  H2CO3,  which  makes  the  sea- 
water  in  the  tidepools  more  acid.  The  average  pH  value  was  7.43 
a  little  before  sunrise.  The  writer  has  never  found  a  good  growth  of 
Fucus  in  seawater  having  as  high  pH  values  as  occur  in  tidepools  during 
the  day  nor  in  seawater  having  as  low  pH  vajues  as  occur  in  tidepools  in 
the  early  morning. 

The  average  temperature  of  the  tidepools  between  1 :00  P.  M.  and 
4:00  P.  M.  was  24.7°.  This  high  temperature  has  already  been  shown 
to  be  harmful  to  Fucus.  When  oospores  were  planted  on  shells  and 
placed  in  the  tidepools  there  was  less  than  a  5  per  cent  germination. 
Those  that  did  germinate  soon  became  loosened  •  from  the  shells.  The 


1919  Gail;  on  Fucus  and  Hydrogen  Ion  301 

only  conditions  of  the  tidepools  measured  by  the  writer  that  were  dif- 
ferent from  those  of  the  surrounding  Fucus  beds  were  temperature  and 
the  pH  values  of  the  seawater  in  the  tidepools.  In  the  light  of  this 
investigation,  these  two  factors  are  believed  to  prevent  the  growth  of 
Fucus  in  tidepools. 

DEPTHS  AT  WHICH  Fucus  GROWS  BELOW  SURFACE  OF  WATER 

It  was  shown  by  experiment  (Gail,  1918)  that  the  oospores,  spore- 
lings,  young  and  mature  plants  of  Fucus  died,  or  that  decomposition  took 
place,  when  suspended  in  the  seawater  of  the  Sound  at  a  depth  greater 
than  1  meter.  The  average  pH  value  of  the  seawater  taken  the  following 
summer  at  the  same  location  and  at  a  depth  of  nearly  1  meter  was  8.0. 
This  is  well  within  the  limits  for  a  good  growth  of  Fucus.  The  pH 
value  of  the  seawater,  however,  does  decrease  with  the  depth.  This 
would  also  indicate  a  low  oxygen  content.  At  the  close  of  the  season  of 
1918,  light  was  believed  to  be  a  controlling  factor,  and  is  still  so  regarded. 
This  is  in  accord  with  Davis  (1911)  who  says  "The  depth  to  which  cer- 
tain algae  may  descend  depends  upon  the  penetration  of  light."  The 
writer  now  considers  that  the  pH  value  and  the  low  oxygen  content  of 
the  seawater  at  the  greater  depths  may  also  be  important  factors.  Lack- 
ing facilities  for  measuring  the  pH  value  and  the  oxygen  content  at  any 
great  depth,  no  accurate  measurements  could  be  made. 


302  Pub.  Puget  Sound  Biol.  Sta.  VOL.  2,  No.  51 

SUMMARY 

1.  The  growth  of  sporelings  as  well  as  larger  plants   of  Fucus  is 
almost  completely  inhibited  in  seawater  having  a  higher  pH  value  than 
8.6,  and  is  very  much  inhibited  in  seawater  having  a  higher  pH  value 
than  8.4. 

2.  Sporelings   as    well   as   larger   plants   of   Fucus   will  not  live   in 
seawater   having   a   pH    value    of    8.6    when   the   temperature   is    higher 
than  24°C. 

3.  Sporelings    as    well   as    larger    plants    of    Fucus    are   very    much 
inhibited  in  growth  when  the  pH  value  of  the  water  is  below  7.2.     Neither 
will  live  in  seawater  having  a  pH  value  of  7.0  when  the  temperature  is 
above    24°C. 

4.  Fucus  is  not  found  on  beaches,  even  tho  there  be  good  attach- 
ment,  where  there  is  much  growth  of  Ulva,  since.  Ulva  causes  the   sea- 
water  to  have  too  high  pH  values. 

/>.  The  results  of  the  experiments  on  permeability  of  the  oospores 
indicate  that  the  plasma  membrane  is  sufficiently  permeable  to  OH  and 
H  ions  in  seawater  having  pH  values  above  8.4  and  below  6.8  to  reduce 
the  percent  of  germination  and  to  inhibit  the  growth  of  sporelings. 

6.  Fucus    is   not    found   on    smooth    gravel   on   beaches    even   where 
Ulva  is  not  present,  since  the  high  temperatures  and  extreme  desiccation 
decrease  the  germination  and  prevent  the  growth  of  sporelings. 

7.  The   oospores  of  Fucus  in  seawater  having  a   pH   value  of   7.0 
do  not  germinate  if  the  the  temperature  is  as  high  as  30°C  for  three  hours 
or   longer.      Germination   is   retarded   at  lower  temperatures   in  seawater 
having  pH   values  below  7.2. 

8.  Fucus  is  not  found  in  tidepools  because  the  temperature  of  the 
water  is  too  high  and  because  the  extremes  of  the  pH  values  of  the  water 
are   too   far   apart. 

9.  Reduced   light  is   a   controlling   factor  in   determining  the   lower 
bow. 

limit   of   Fucus.      The   probable   low   pH   value   and   low   oxygen   content 
of  the   seawater  at   any   considerable   depth  may  also  be  important   fac- 


1919  Gail;  on  Fucus  and  Hydrogen  Ion  303 

BIBLIOGRAPHY 
Chambers,  C.  O. 

1912.  The  relation  of  algae  to  dissolved  oxygen  and  carbon  dioxide 
with  special  reference  to  carbonates.  23rd  Annual  Rep. 
Missouri  Bot.  Garden,  pp.  171-207. 

Child,  C.  M. 

1915.  Senescence  and  rejuvenescence.  University  of  Chicago 
Press. 

Clafk,  W.  M.,  and  Lubs,  H.  A. 

1917.  The  colorimetric  determination  of  hydrogen  ion  concentration. 

Jour.   Bact.,  Vol.   2,   pp.   1-34,   109-136,   191-236. 

Cohen,  B.,  and  Clark,  W.  M. 

1919.  The  growth  of  certain  bacteria  in  media  of  different  hydro- 
gen ion  concentration.  Jour.  Bact.,  Vol.  4,  pp.  409-427. 

Davis,  B.  M. 

1911.  General  characteristics  of  the  algal  vegetation  of  Buzzards 
Bay  and  Vineyard  Sound  in  the  vicinity  of  Woods  Hole. 
Bull.  U.  S.  Bureau  Fisheries,  Vol.  31,  pp.  443-475. 

Gail,  F.  W. 

1918.  Some  experiments   with  Fucus  to  determine  the  factors  con- 

trolling its   vertical   distribution.      Pub.   Puget  Sound   Biol. 
Sta.,  Vol.  2,  pp.  139-151. 
Gillespie,  L.  J. 

1918.  The  growth  of  the  potato  scab  organism  at  various  hydrogen 

ion   concentrations   as   related   to  the   comparative   freedom 

of  acid   soils   from  the  potato  scab.      Phytopathology,  Vol. 

8,   pp.   257-269. 
Harvey,  E.  N. 

1911.     Studies  on  permeability  of  cells.     Jour.  Exp.  Zool.,  Vol.  10, 

pp.  507-521. 
Itano,  A.,  and  Neill,  J. 

1919.  The    influence   of   temperature   and    hydrogen   ion   concentra- 

tion upon  the  spore  cycle  of  Bacillus  subtilis.     Jour.  Gen. 
Physiol.,  Vol.   1,  pp.  421-428. 
Loeb,  J. 

1907.     Chemical    character    of   the    process    of    fertilization   and    its 
bearing    on  •  the   theory    of    life    phenomena.      Univ.    Calif. 
Pub.  Physiol.,  Vol.  3,  pp.  61-81. 
Long,  E.  R. 

1915.  Growth  and  colloid  hydration  in  cacti.  Bot.  Gaz.,  Vol.  59, 
pp.  491-497. 

Shelford,  V.  E. 

1918.  The  relation  of  marine  fishes  to  acids  with  particular  reference 
to  the  Miles  Acid  Process  of  sewage  treatment.  Pub. 
Puget  Sound  Biol.  Staf,  Vol.  2,  pp.  97-111. 


304  Pub.  Pugei  Sound  Biol.  Sta.  VOL.  2,  No.  51 

I  wish  to  express  my  appreciation  of  Dr.  T.  C.  Frye,  Professor  of 
Botany  in  the  University  of  Washington,  at  whose  suggestion  this  work 
was  undertaken,  for  his  interest  and  able  suggestions.  I  am  grateful  to 
Dr.  G.  B.  Rigg,  of  the  University  of  Washington,  and  Dr.  C.  M.  Child, 
of  the  University  of  Chicago,  for  helpful  assistance;  acknowledgment 
is  also  due  to  Dr.  C.  L.  von  Ende,  Professor  of  Chemistry  in  the  Univer- 
sity of  Idaho,  for  providing  all  needed  facilities  for  the  preparation  of 
chemicals  and  for  helpful  advice. 


1919 


Gail;  on  Fucus  and  Hydrogen  Ion 


305 


.72 


Growth  of  sporelings  when  #** 
temperature  varied  from  II  C.  to  // 1. 


Days 


PLATE  51 


306 


Pub.  Puget  Sound  Biol.  Sta.  VOL.  2,  No.  fil 


Graphic  representation  of  size  of  sporelings  after  4  weeks. 


8.4 
8.0-8.2 


70 


I0.5°C.-I3°C. 


tl°C.-24°C        H°C.-30°C. 


Graphic  representation  of  per  cent          Graphic  representation  of  per  cent 
zrm/r/ation  of  oospores.  of  living  sporelings  after  4-  weeks. 


io.5v.-iyc.  irc-irc  //K&t  iit-wc.      tarc-irc  /rc-/7t  //K-&K /rc-wc 

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